Method for evaluating a test fluid

ABSTRACT

A method for evaluating a test fluid as a fabric care composition or as a component thereof. The method includes providing a test sheet of fabric comprising a plurality of test regions and simultaneously contacting each of the plurality of test regions with a different test fluid. The method further includes screening the plurality of test regions or the contacted test fluids for a fabric property of interest to evaluate the relative efficacy of the different test fluids.

BACKGROUND OF THE INVENTION

[0001] The present invention relates generally to methods for evaluatinga test fluid, and more particularly, to methods for testing compositionsin contact with a test sheet of fabric.

[0002] Testing of chemical formulations often involves exposing thechemicals to a porous material such as a fabric which absorbs orinteracts with the chemicals. Developers of fabric care products, forexample, test different chemical compositions and formulations byexposing pieces of fabric to the compositions or formulations, andmeasuring the effects on the fabric's appearance, physical, or chemicalproperties which result. The types of chemicals or compositions testedin this way may include surfactants, polymers, dyes, bleaches, perfumes,buffers, electrolytes, builders (e.g., calcium sequestering agents),flame retarding agents, and others. Some of the benefits which may bedesirable to deliver with such compositions, and which are thereforedesirable to measure after exposing the fabric to the compositions orformulations, include release or removal of soils and stains, dyeretention by a fabric during washing, prevention of dye transfer fromone fabric to another, prevention of soil redeposition, resistance tothe abrasion which occurs due to fabrics rubbing against each otherduring washing, building up of fibers to increase the life of a garment,reduction or prevention of wrinkles, reduction or prevention of staticbuildup, and improvement or preservation of the feel or texture of afabric.

[0003] Currently used methods of testing for such benefits are extremelylaborious, and limit the rate at which new compositions and formulationscan be tested. The slowest testing methods involve washing fabrics inconventional full sized washing machines, or doing hand washing in abasin. Some degree of miniaturization has been introduced through theuse of instruments such as the Washtec Linitester (manufactured byRoaches) or the Turgotometer (manufactured by Heraeus). In theseinstruments, washing is done in vessels of reduced volume, typically0.5-2 liters, and multiple vessels are tested simultaneously. Forexample, the Heraeus Turgotometer consists of six one liter potsarranged in a straight line, each with an overhead stirrer to provideagitation similar to that found in top-loading washing machines. In theRoaches Washtec, up to twelve 1 liter vessels are mounted radially on acentral axel, which is rotated to give an end-over-end tumbling motionand provide agitation. In both cases, the temperature is controlledthrough a thermostatted bath which surrounds the vessels.

[0004] Although these instruments represent a significant improvementover testing methods which utilize full scale washing apparatus, theystill require a tremendous amount of manual labor, take up a great dealof space, and have limited throughput. Detergent formulations areextremely complex, often consisting of ten or more ingredients. Whilesignificant improvements in detergent performance can be and have beenattained by introducing new ingredients or changing formulations, thesize of the parameter space to be tested is enormous, includingvariables related to both chemical structure and formulations. It istherefore, desirable to develop methods and apparatus which allowhigh-throughput testing of compositions and formulations for fabriccare. Ideally, it is desirable to obtain high throughput andminiaturization without sacrificing relevance of the results to morerealistic conditions.

[0005] One possible method of high throughput testing of fabric carecompositions and formulations is to place small, individual pieces offabric in an array of small vessels, e.g. in a microtiter plate. Onedrawback to this method is that the individual pieces of fabric aredifficult to handle and must be left in the wells during subsequent,handling, treatment, and analysis. If the pieces of fabric are removedfrom the wells, special handling equipment is required. Also, each pieceof fabric may need to be individually labeled to preventmisidentification of the composition used to soak the fabric.Furthermore, it is difficult to simulate the agitation of fabric withina washing machine since the fabric is simply soaking in the fluid.

[0006] There is, therefore, a need for a method for testing compositionsin parallel with a continuous sheet of porous material having aplurality of test regions, which can be easily analyzed upon completionof testing. There is also a need for a method for forcing fluid throughthe porous material or in contact with the material to simulateagitation of the porous material within the fluid

SUMMARY OF THE INVENTION

[0007] Methods for testing compositions in contact with a porous mediumare disclosed. The methods improve the productivity in testingvariations of compounds by permitting large numbers of compositions tobe tested simultaneously (in “parallel”), in an efficient manner that isamenable to various forms of automation to provide high-throughput.

[0008] A method for evaluating a test fluid as a fabric care compositionor as a component thereof generally comprises providing a test sheet offabric comprising a plurality of test regions and simultaneouslycontacting each of the plurality of test regions with a different testfluid. The method further includes screening the plurality of testregions or the contacted test fluids for a fabric property of interestto evaluate the relative efficacy of the different test fluids.

[0009] Two or more test sheets of fabric may be provided and each sheetmay comprise a plurality of test regions. Each of the test regions maybe the same or the regions may be different from one another. Theplurality of test regions may be substantially isolated from oneanother. The plurality of test regions may be screened for a fabricproperty of interest, the contacted test fluids may be screened for afabric property of interest, or both the test regions and fluids may bescreened. The plurality of test regions may be screened using aspectroscopic technique, for example.

[0010] In another aspect of the invention, a method generally comprisesproviding a test sheet of fabric comprising a plurality of test regions,each of the plurality of test regions comprising a different fabriccomposition and simultaneously contacting each of the plurality of testregions with a test fluid. The method further includes screening theplurality of test regions or the contacted test fluids for a fabricproperty of interest to evaluate the relative efficacy of the differentfabric compositions.

[0011] The method may further include simultaneously treating each ofthe plurality of test regions with a plurality of treatment fluids, theplurality of treatment fluids differing between the plurality of testregions. The different fabric compositions may comprise one or morepolymers adsorbed onto a fabric with the one or more polymers varyingbetween the different fabric compositions.

[0012] In yet another aspect of the invention, a method for preparing atreated fabric array generally comprises providing a test sheet offabric comprising a plurality of test regions and simultaneouslycontacting each of the plurality of test regions with a plurality oftreatment fluids, the plurality of treatment fluids differing betweenthe plurality of test regions. The method further includes allowing oneor more components of a plurality of treatment fluids to interact withthe test sheet of fabric at the plurality of test regions.

[0013] The plurality of treatment fluids may comprise a polymercomponent which varies between different treatment fluids with respectto composition, hydrophilicity, molecular weight, or molecular weightdistribution.

[0014] The above is a brief description of some deficiencies in theprior art and advantages of the present invention. Other features,advantages, and embodiments of the invention will be apparent to thoseskilled in the art from the following description, drawings, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1A is an exploded perspective of one embodiment of anapparatus of the present invention.

[0016]FIG. 1B is an exploded perspective of the apparatus of FIG. 1Awith one porous sheet and a sealing sheet removed.

[0017]FIG. 1C is an exploded perspective of the apparatus of FIG. 1Bwith a central plate removed.

[0018]FIG. 2A is a partial cross-sectional view of the apparatus of FIG.1B.

[0019]FIG. 2B is a cross-sectional view of the apparatus of FIG. 1C.

[0020]FIG. 2C is a cross-sectional view of the apparatus of FIG. 1C witha vacuum applied to cavities within the apparatus.

[0021]FIG. 2D is a cross-sectional view of the apparatus of FIG. 2B withfluid passages replaced with a common chamber.

[0022]FIG. 2E is a cross-sectional view of the apparatus of FIG. 2A withmovable rods attached to a flexible membrane to flex the membrane.

[0023]FIG. 3 is a plan view of a test fabric having seal materialimprinted thereon for use with the apparatus of FIG. 1.

[0024]FIG. 4 is an exploded perspective of a second embodiment of theapparatus of the present invention.

[0025]FIG. 5 is a schematic of a pneumatic circuit used to applypressure to the apparatus of FIGS. 1 and 4.

[0026]FIG. 6 is a cross-sectional view of a third embodiment of theapparatus of the present invention.

[0027]FIG. 7A is a flowchart illustrating a process for preparing a testsheet.

[0028]FIG. 7B is a flowchart illustrating a process for testingcompositions with the apparatus of FIGS. 1 and 4.

[0029]FIG. 8 is a plan view of a test sheet without an integral sealused in a first experiment (IA).

[0030]FIG. 9 is a plan view of a test sheet with an integral seal usedin a second experiment (IB).

[0031]FIG. 10 is a plan view of a test sheet without an integral sealused in a third experiment (IIA).

[0032]FIG. 11 is a plan view of a test sheet with an integral seal usedin a fourth experiment (IIB).

[0033]FIG. 12 is a table (Table I) listing a library of different testfluids for an experiment described below in Example 3.

[0034]FIG. 13A is a plan view of a test sheet used in testing thelibraries listed in FIG. 12.

[0035]FIG. 13B is a plan view showing liquid which was in contact withtest regions of the test sheet of FIG. 13A.

[0036]FIG. 14 is a table (Table II) listing red-green-blue spectrumanalysis coordinates from the test regions of the test sheet shown inFIG. 13A.

[0037]FIG. 15 is a graph showing spectra data for the liquid samplesshown in FIG. 13B.

[0038]FIG. 16A is a graph illustrating the effect of polymerconcentration with no surfactant.

[0039]FIG. 16B is a graph illustrating the effect of surfactantconcentration with polymer concentration fixed at 100 ppm.

[0040]FIG. 16C is a graph illustrating fabric reflectance.

[0041]FIG. 16D is a graph illustrating liquid absorbance.

[0042] Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

DETAILED DESCRIPTION OF THE INVENTION

[0043] The following description is presented to enable one of ordinaryskill in the art to make and use the invention. Descriptions of specificembodiments and applications are provided only as examples and variousmodifications will be readily apparent to those skilled in the art. Thegeneral principles described herein may be applied to other embodimentsand applications without departing from the scope of the invention.Thus, the present invention is not to be limited to the embodimentsshown, but is to be accorded the widest scope consistent with theprinciples and features described herein. For purpose of clarity,details relating to technical material that is known in the technicalfields related to the invention have not been described in detail.

[0044] Referring now to the drawings, and first to FIGS. 1A, 1B, and 1C,an apparatus, generally indicated at 20, for use in testing a pluralityof compositions in parallel is shown. The apparatus 20 may be used, forexample, in testing fabric care chemicals such as anti-dye transferpolymers, dye absorbers, pretreatment agents, or stain guard agents. Thefabric care chemicals may be used in laundry detergents or stain guardproducts used to pretreat clothing or other material such as upholstery.For example, the chemical composition may be optimized for use incleaning dyed fabrics for removing soil and stains while retainingbrightness and resisting dye loss from the fabric or dye transfer fromone fabric to another. The compositions may be gas, liquid, or foam, orthey may be solid or granular compounds designed to dissolve in water,for example. The compositions to be tested may also be located on thefabric with the same fluid used to test the various compositions. It isto be understood that the compositions and applications described hereinare merely examples of uses for the apparatus and methods of the presentinvention, and that the invention may be used in other applicationswithout departing from the scope of the invention. The apparatus andmethods of the present invention may be used for applications in whichit is desirable to create fluid movement through a porous medium orprevent fluid transfer between distinct regions of the porous medium.

[0045] As shown in FIG. 1A, the apparatus 20 includes a lower plate 22,central plate 24, upper plate 26, and cover plate 28, each having anarray of openings. The plates 22, 24, 26, 28 are stacked with theopenings in axial alignment with one another. The plates 22, 24, 26, 28preferably include ninety-six openings (or multiples of ninety-six)arranged to correspond to a standard microtiter plate format. The numberof test regions is preferably at least 4, 8, 15, 24, 40, 60, 90, 100,200, 400, 500, 1000, 2000, 4,000, 10,000 or more. In preferredembodiments, the number of test regions=96*N, where N is an integerranging from 1 to 100, preferably 1-10, and more preferably 1-5.Openings 30 extend through the corners of plates 22, 24, 26, 28 forreceiving a screw, bolt, or other suitable attachment means 34 to holdthe assembly together. The bolt 34 is preferably recessed within thelower plate 22 and cover plate 28 to prevent anything from protrudingfrom the plates so that the apparatus can be used with equipmentdesigned for devices having a conventional microplate format. The lower,central, and upper plates 22, 24, 26 also include alignment holes 60 forreceiving an alignment pin 62 used to align components of the apparatus20. The plates 22, 24, 26, 28 may have a thickness of between 0.063 and6.0 inches and be formed from aluminum, titanium, steel, Teflon, ornylon, for example. The plates (or block) 22, 24, 26, 28 may be formedas a solid piece or from a laminate construction. For example, openingsmay be formed in only a portion of the laminate layers so that theopenings extend only partially through the plate. An upper surface oflower plate 22 may have a thin honeycomb structure which opens up to onelarge cavity 29 within a lower portion of the plate (FIG. 2D). Theopenings in the plates 22, 24, 26, 28 may be lined with an inert linerto prevent reactions between chemicals and the plate material. It is tobe understood that the arrangement or number of openings and thematerial of the plates 22, 24, 26, 28 may be different than shown anddescribed herein without departing from the scope of the invention. Forexample, the plates may have fewer than ninety-six reaction wells. Also,the position of the upper and lower plates 22, 26 may be switched (i.e.,the apparatus may be used in an inverted position as compared to thatshown in FIG. 1A).

[0046] The openings in the lower plate 22 extend only partially throughthe plate to form cavities 40 which are interconnected with one anotherthrough passages 42 within the plate (FIGS. 1A and 2A). The passages 42are connected to an inlet 46 for applying pressure or vacuum to thecavities 40 and a flexible membrane 50 interposed between the lower andcentral plates 22, 24, as further described below. The cavities 40within the lower plate 22 are aligned with central fluid chambers 52formed by the openings extending through the central plate 24. Theopenings extending through the upper plate 26 form upper fluid chambers54 which are in alignment with both the central fluid chambers 52 andthe cavities 40. The cover plate 28 includes a plurality of cylindricalopenings 56 sized for receiving a pipette or similar tool for insertingfluid into the upper fluid chambers 54. The fluid chambers 52, 54 mayeach have a fluid volume of between 0.1 milliliters and 5 milliliters,for example.

[0047] The apparatus 20 further includes a sheet 64 interposed betweenthe central plate 24 and the upper plate 26. The sheet 64 includes aplurality of test regions 68. The test regions 68 may all have the samecomposition for testing different compositions of the fluid or each ofthe fluid chambers 54 may contain the same fluid with the test regionseach having different compositions contained thereon. As shown in FIG.1A, the apparatus may include two sheets 64. One sheet may have whitetest regions and the other sheet may have dyed test regions, forexample. The apparatus may also be configured to test the interactionbetween only a single sheet 64 and fluid within the fluid chambers 52,54 as shown in FIG. 1B. The sheet 64 is preferably porous to allow fluidwithin the fluid chambers 52, 54 to pass therethrough. The sheet 64 mayalso be formed from a nonporous material in which case the fluid willnot flow through the sheet, but will be agitated by pressurization ofthe fluid within the fluid chambers 52, as described below.

[0048] The porous sheet 64 may be formed at least partially from afabric (e.g., cotton, polyester, rayon) silica, alumina, filter media(e.g., cellulose, quartz matte) ceramic, sintered metals, plastics orany other porous material or combination of materials. The porousmaterial may be woven fabric (e.g., 30-350 threads per inch), forexample. The sheet 64 may be flexible or rigid. The sheet may alsoinclude non-porous regions having a porous material (e.g., fabric,catalyst, etc.) at or on the test regions. The sheet 64 includesalignment openings 72 for receiving the alignment pins 62 so that thetest regions 68 in the sheet 64 can be properly aligned with the fluidchambers 52, 54 in the central and upper plates 24, 26, respectively(FIGS. 1 and 3). The sheet 64 also includes openings 74 for receivingscrews 34.

[0049] As shown in FIG. 3, the porous sheet 64 includes a seal 70 whichis integral with the porous material and separates the test regions 68.The seal 70 is applied to the fabric in a pattern to form test regions68 corresponding generally in size and shape to the central and upperfluid chambers 52, 54, as viewed in transverse cross-section. The seal70 defines the individual test regions 68 and prevents transfer of fluidbetween the test regions and cross talk of fluid between adjacent fluidchambers. When the test apparatus 20 is assembled, the periphery edgesof the fluid chambers 52, 54 contact the seal 70 of the porous sheet 64to prevent fluid from transferring between adjacent chambers either byseeping between the seal and chamber edges or bleeding through thefabric. Thus, continuous sheet 64 can be placed in contact withdifferent solutions without cross contamination between the solutionsand test regions 68 of the fabric. It is to be understood that the testregions may have shapes or sizes different than shown herein withoutdeparting from the scope of the invention. For example, the testregions, cavities, and fluid chambers may be circular, rectangular,oblong, triangular, or any other shape.

[0050] The seal 70 is formed from a material that penetrates the fabricto substantially fill the pores and can be physically or chemicallysolidified (e.g., cross-linked by some means such as curing to render itinsoluble). The seal material is preferably selected so that it does notreact with the test fluid and remains adhered to the porous materialduring testing and subsequent analysis. The seal 70 may be formed from athermoplastic material that can be melted and flowed into fibers of thefabric to bond the sealing material to the fabric. Silk screening mayalso be used to bond the sealing material to the fabric. For example,the seal 70 may be formed from a plastisol ink available from Union Inkof Ridgefield, N.J., under the trade name Ultrasoft. Plastisol ink iscomprised primarily of PVC resin and a plasticizer. The ink wraps aroundthe fibers and makes a mechanical bond with the fabric. If nylonmaterial is used as the porous material, a bonding agent may need to beadded to the seal material. When the plastisol is heated (e.g., 138-160°C.), the resin particles absorb the surrounding liquid (plasticizer) andswell to merge with one another to form a tough, elastic film. The inkmay be applied by standard screen screening techniques, heat transferprinting, or molding, for example. The ink may also be cured byultraviolet light or air dried instead of high temperature curing whichmay impact fabric strength or other fabric properties. It is to beunderstood that seal materials and methods for applying the seal 70different than those described herein may be used without departing fromthe scope of the invention.

[0051] As shown in FIG. 1A, two porous sheets 64 may be placed at onetime in the test apparatus 20 with an optional sealing sheet 76 placedin between the two porous sheets. The test regions 68 of one of theporous sheets 64 may optionally contain a dye (e.g., red colored dye)while the test regions of the other porous sheet are white. This allowsthe dye transfer between two fabrics to be analyzed. In applicationssuch as pretreating test regions 68 or testing the cleaning ability of adetergent, only one porous sheet 64 is required (FIG. 1B). In someapplications more than two porous sheets 64 (e.g., six sheets, greaterthan ten sheets) may be utilized with or without sealing sheets 76interposed therebetween. The porous sheet 64 may be stained with oil ormakeup, for example, to test the effectiveness of laundry detergentcompositions. Other applications are described below. The sealing sheet76 may also be placed between the porous sheets 64 and the central orupper plates 24, 26 (FIG. 1A). The sealing sheet 76 may be formed from arubber material that is substantially nonporous and chemically inert tothe compositions being tested. Openings 78 corresponding to the testregions 68 of the porous sheet 64 are punched or cut into the sealingsheet 76 to allow fluid flow therethrough. The sealing sheet 76 providesadditional sealing between periphery edges of the fluid chambers 52, 54and the porous sheet 64 or between two adjacent porous sheets. Alignmentholes 80 are formed in the sealing sheet 76 to allow for properalignment of the sealing sheet 76 with the porous sheets 64 and fluidchambers 52, 54.

[0052]FIG. 4 shows a second embodiment, generally indicated at 84, whichis similar to the first embodiment 20 shown in FIG. 1A, except that aspacer block 86 is interposed between the two porous sheets 64. Also,lower plate 88 and central plate 90 include circular openings 92, 94rather than the rectangular openings of the first embodiment 20. Anupper surface of the lower plate 88 is machined with grooves extendingaround the periphery of openings 92 for receiving o-rings 96. The spacerblock 86 and central plate 90 include raised edges (or o-rings) 98extending around the openings 93, 94. The distance between the raisededges 98 is preferably the same as or larger than the width of the testregions 68 of the porous sheets 64 so that when the sheet is placed ontop of the raised edges, the raised edges make contact with the seal 70of the sheet. The spacer block 86 may also be used with the testapparatus 20 shown in FIG. 1A. Also, the circular openings may be usedon only one of the plates 88, 90 or spacer block 86, or any combinationthereof.

[0053] As previously described, the test regions 68 of the sheet 64 arepreferably permeable to allow fluid to pass therethrough. In order tocreate fluid agitation, the fluid within chambers 52, 54 may be forcedthrough the test regions 68 by applying a vacuum or pressure (or both)to the cavities 40 below the flexible membrane 50 (FIGS. 1A and 2A). Asupply line providing pressure, vacuum, or both pressure and vacuum, isattached to the inlet 46 in the lower plate 22. The inlet 46 is incommunication with the cavities 40 through the passages 42 formed in thelower plate 22. Fluid movement through the test regions 68 of the poroussheet 64 is caused by pressure or vacuum flexing the flexible membrane50. When pressure is applied to the cavities 40, the flexible membraneflexes upwardly towards the porous sheet 64, thus increasing pressure inthe central chambers 52 and forcing fluid from the central chambers intothe upper chambers 54. When a vacuum is applied to cavities 40, theflexible membrane 50 is pulled downwardly into the cavities, thusdecreasing pressure in the central chambers 52 and drawing fluid intothe central chambers from the upper chambers 54. It is to be understoodthat rather than cycling between pressure and vacuum, only one of thepressure and vacuum may be cycled on and off. A second flexible membrane(not shown) may also be placed at the open end of the upper fluidchambers 54 and cycled with pressure and vacuum in conjunction with theapplication of pressure and vacuum to the lower cavities 40 to force thefluid through the test regions 68.

[0054] As shown in FIGS. 1C and 2B, the central plate 24 may be removedand the porous sheet 64 positioned adjacent to the flexible membrane 50.The flexible membrane 50 is drawn away from the porous sheet 64 by theapplication of a vacuum to cavities 40 (FIG. 2C). A fluid volume is thusdefined by the flexible membrane 50 and porous sheet 64 and the fluid isdrawn through the porous sheet from the upper fluid chambers 54 into thelower fluid chambers 40 when a vacuum is created in the cavities. Fluidagitation is created by cycling the vacuum (and pressure) on and off toforce the fluid back and forth through the porous sheet 64.

[0055] Pressure may also be applied to the upper chambers 54 to forcethe fluid through the porous sheet and cause the flexible membrane 50 toflex and provide a space for the fluid. The pressure applied to theupper chambers may also be cycled on and off to force the fluid back andforth through the porous sheet 64.

[0056] The membrane 50 may also be flexed by mechanical means ratherthan by applying a pressure or vacuum. For example, push-pull rods 71may be attached to the membrane 50 at a location within each of thecavities 40 of the lower plate, as shown in FIG. 2E. The rods arefixedly attached to a central actuator 73 which operates to move each ofthe rods axially to flex the membrane 50 towards and away from theporous sheet 64. The actuator may be a linear or rotary actuator andpowered by pneumatic, hydraulic, or electrical means, for example. Therods 71 may each have a piston at an upper end thereof to contact alarger surface area of the membrane 50, for example. The rods 71 may becoupled to the membrane 50 by adhesive or other attachment means so thatthe rods can move the membrane in opposite directions, or the rods maybe separate from the membrane and used only to flex the membrane in adirection towards the porous sheet 64.

[0057] The flexible membrane 50 is preferably formed from an elasticmaterial that is nonporous and chemically inert to the compositionsbeing tested. For example, the membrane 50 may be formed from silicone,latex, or nitrite and have a thickness of 0.004-0.010 inches. Themembrane 50 is preferably sufficiently flexible (e.g., capable ofstretching at least 400% of its resting state length) so that it canextend at least partially into the central fluid chamber 52 (as shown inphantom in the left chamber in FIG. 2A) and into the cavity 40 (as shownin phantom in the center cavity in FIG. 2A). The membrane may also bepreformed so that the membrane can flex without requiring significantstretching of the material. The membrane 50 may deflect longitudinallyapproximately 1 mm to 10 mm into chamber 52 or cavity 40 to displaceapproximately 0.01 ml to 1 ml of fluid.

[0058]FIG. 5 illustrates an example of a pneumatic circuit 100 that maybe used to apply pressure and vacuum to the apparatus 20, 84. Thecircuit includes three solenoid valves 102, 104, 106, air pressureregulators 108, 110, a vacuum generator 112, and an electroniccontroller, generally indicated at 112. The electronic controller 112includes a cycle timer 114, which controls the solenoid valves 102, 104,106 and an event timer 116. The event timer 116 starts the cycle timer114 at the beginning of the test and stops the cycle timer at the end ofthe test. The cycle timer 114 sequentially opens and closes the pressureand vacuum solenoid valves 102, 104 and changes position of the controlsolenoid valve 106 to provide pressure and vacuum to the test apparatus20. Pressurized air (e.g., 80-100 psig.) is provided to the circuit 100from an external source (not shown). Pressure regulator 108 ispositioned upstream of pressure solenoid valve 102, which includes aninlet port 120 and an outlet port 122. When the pressure solenoid valve102 is energized it connects ports 120 and 122 to provide flow tocontrol solenoid valve 106, which ports pressure from inlet port 126 tooutlet port 130 in its pressure position. Pressure regulator 112 ispositioned upstream of vacuum solenoid valve 104 which includes inletport 132 and outlet port 134. The vacuum generator 112 is positionedbetween the pressure regulator 110 and the vacuum solenoid valve 104 tocreate approximately 25 inch Hg of vacuum. The vacuum solenoid valve 104supplies a vacuum at port 134, which is connected to the controlsolenoid valve 106, when the vacuum solenoid is in its energizedposition. The control solenoid valve 106 connects ports 128 and 130 whenin its vacuum position to provide a vacuum to the test apparatus 20.

[0059] The cycle timer 114 is preferably programmed to first energizethe vacuum solenoid valve 104 and place the control solenoid valve 106in its vacuum position (connecting ports 128 and 130) while deenergizingthe pressure solenoid valve 102. The cycle timer 114 next energizes thepressure solenoid valve 102 and places the control solenoid valve 106 inits pressure position (connecting ports 126 and 130), while deenergizingthe vacuum solenoid valve 104. The event timer 116 may run the cycletimer 114 through 1800 to 3600 pressure and vacuum cycles, with eachcycle lasting approximately ½ second, for example. It is to beunderstood that the circuit 100 shown in FIG. 5 and the operationdescribed herein are provided for purposes of illustration only. One ofordinary skill in the art will readily appreciate that other systems maybe used to supply pressure and vacuum to the test apparatus 20. Forexample, liquid may be used to pressurize the cavities 40 instead ofgas.

[0060] A third embodiment of the test apparatus is shown in FIG. 6 andgenerally indicated at 150. The apparatus includes a lower plate 152, acentral plate 154, and an upper plate 156. Central plate 154 includes anarray of openings extending therethrough to form fluid chambers 160. Inone embodiment, a first porous sheet 64 is placed between the lowerplate 152 and central plate 154, and an optional second porous sheet isplaced between the central plate 154 and upper plate 156. Optionalsealing sheets 76 are placed between the lower plate 152 and the firstporous sheet 64, and upper plate 156 and the second porous sheet. Eachplate 152, 154, 156 includes openings 168 for receiving screws or othersuitable attachment means. In order to assemble apparatus 150, theoptional sealing sheet 76 and first porous sheet 64 are placed on top ofthe lower plate 152. The central plate 154 is then positioned over thefirst porous sheet 64. The test fluids are placed into their respectivefluid chambers 160 and the second porous sheet 64 and sealing sheet 76are placed over the central plate 154. The upper plate 156 is positionedover the sealing sheet 76 and screws (not shown) are inserted into thealigned holes 74, 168 in each of the porous sheets 64 and plates 152,154, 156 to force each component into contact with its adjacentcomponent. The assembly 150 may be placed on a shaker or rocker toagitate the fluid and increase contact between the fluid particles andthe test regions 68. Mixing balls may also be inserted into each fluidchamber 160 to agitate the fluid. An array of parallel plungers (e.g.,syringes) (not shown) may be used to agitate the fluid. The syringes maybe used to pressurize fluid similar to the flexible membrane of theprevious embodiments.

[0061] The apparatus may be inserted into a test station which includesconnections for pneumatic supply lines and temperature control. Forexample, a test station may comprise a base sized for receiving aplurality of test blocks (e.g., four test apparatuses). Thepressure/vacuum inlet may be located on a bottom surface of the lowerplate 22 and aligned with a pressure/vacuum coupling on a bottom of thebase. The pressure/vacuum coupling is in fluid communication with asupply line connected to the base. The base may also be configured forheating the test blocks. The test station may also include a cover(e.g., a clear plastic plate) that is placed over the test blocks andattached to the base of the test station. The cover may include anopening for receiving pressure for pressurizing fluid within the fluidchambers 54 to force the fluid through the porous sheet 64. The teststations facilitate quick connection and removal of the test blocks fromthe pneumatic supply and allow for testing of multiple test blocks atone time.

[0062]FIG. 7A is a flowchart illustrating a process for preparing a testsheet and FIG. 7B is a flowchart illustrating a process for testing aplurality of compositions in parallel using the apparatus shown in FIGS.1A, 1B, 1C, or 4. The fabric is first dyed if the test regions 68 of theporous sheet 64 are to be colored (step 200). The design shown in FIG. 3is printed with the seal material on transfer paper (step 202). Thetransfer paper is passed through a conveyer dryer or other suitablecuring equipment where the seal material is heated until it has gelledenough to be dry to the touch. The printed transfer paper is next placedin a press adjacent to the fabric. Heat and pressure is applied to theprint and fabric to force the seal material into the fabric and completethe curing process (step 204). The press is then opened and the paper ispeeled off of the fabric with the seal 70 remaining on the fabric. Thefabric may then be cut to form individual porous sheets 64 (step 206). Atemplate cutter may be used to punch alignment and screw holes 72, 74into the porous sheets 64. It is to be understood that processesdifferent than those described herein may be used to form the test sheet64 without departing from the scope of the invention. For example, theseal may be applied directly to the fabric without the use of transferpaper and heat cured or dried by exposure to light or air. Inparticular, screen print methods may be used as described below inExample 1.

[0063] The apparatus 20 is then assembled as generally shown in FIGS.1A, 1B, and 1C (depending on the embodiment). The flexible membrane 50is first positioned over the lower plate 22 with the alignment pins 62extending through the alignment holes in the membrane at step 207 (FIG.7B). The central plate 24 is next placed (if used) over the flexiblemembrane 50 (step 208). One or more porous sheets 64 along with one ormore optional sealing sheets 76 are placed over the central plate 24using the alignment holes 72, 80 and pins 62 to align the sheets withthe plate (step 209). The upper plate 26 is placed over the poroussheets 64 and test samples are placed within each of the upper fluidchambers 54 (step 210). The cover plate 28 is optionally placed on topof the upper plate and screws 34 are then inserted into the alignedopenings 30, 74 and tightened to force the sheets 64 into sealingengagement with the adjacent plates 24, 26 (step 211). The apparatus maybe optionally placed into an oven or heating block to preheat the fluidto approximately 40° C., for example.

[0064] The circuit 100 is connected to the inlet 46 of the apparatus atstep 212 (FIGS. 1A, 5, and 7). The event timer 116 is started and thecircuit 100 provides pressure and vacuum to the cavities 40 (step 213).After the cycles are completed, the circuit 100 is disconnected from theapparatus and the cover plate 28 (if in place) is removed (step 214). Asample of each test fluid is removed from the upper fluid chambers 54.The remaining fluid is then removed by turning the apparatus 20 upsidedown and allowing the fluid to drain from the upper fluid chambers 54(step 216). The chambers 54 may also be rinsed to ensure that all thetest fluid is removed (step 218). The apparatus 20 may then be left tosit assembled for a period of time to allow the test regions 68 to dryto prevent fluid from transferring between adjacent test regions whenthe apparatus is disassembled. After the porous sheet 64 has dried, theapparatus 20 is disassembled and the porous sheets removed (step 220).

[0065] The test regions 68 may be visually examined to providequalitative results and scanned to obtain reflectance spectra data forquantitative analysis (step 222). The spectral reflectance may be usedto derive color density values and colorimetric parameters, for example.The liquid removed from the individual wells may also be analyzed todetermine the amount of dye that was removed from the fabric during thetest.

[0066] The apparatus 20, 84, 150 may be used to test a plurality ofagents having varying compositions so that the compositions can bequickly narrowed down to the most effective formulations. For example,the apparatus 20, 84, 150 may be used to select a particular polymer,determine the best concentration, and adjust a ratio of surfactants. Thecompositions exhibiting the most favorable results may then be putthrough additional testing, such as by placing a large piece of fabricin a container filled with the solution and shaking the container, orplacing the fabric in a conventional washing machine.

[0067] In a preferred application, the aforedescribed apparatus may beused in a combinatorial, high-throughput research program directed todeveloping improved fabric-care compositions or components thereof,improved fabric treatments, improved fabric compositions, or directed toother research goals, such as fabric-care process characterizationand/or optimization. Fabric-care compositions are compositions of mattercomprising one or more components having or potentially having utilityin connection with a fabric care application. Exemplary fabric-carecompositions include compositions comprising various laundry aids suchas detergents, soaps, bleaches and softeners, among others. Hence,fabric-care compositions (and likewise, the test fluids used in theresearch program) can include components that are elements, compounds orcompositions, and can typically include, without limitation, polymers,surfactants, dyes, bleaches, perfumes, buffers, electrolytes, builders,sequestering agents, flame retardants, and/or enzymes alone or invarious combinations and permutations. The fabric care compositions arepreferably liquids (e.g., solutions, dispersions, or emulsions), but canalso be solids or, in some applications, gases.

[0068] Combinatorial (i.e., high-throughput) approaches for screening alibraries of materials for applications as components of fabric-carecompositions may include an initial, primary screening, in which varioustest fluids and/or fabrics are rapidly evaluated to provide valuablepreliminary data and, optimally, to identify several “hits”—particularcandidate materials having characteristics that meet or exceed certainpredetermined metrics (e.g., performance characteristics, desirableproperties, unexpected and/or unusual properties, etc.). Such metricsmay be defined, for example, by the characteristics or properties of aknown or standard fabric care compositions or of a known fabrics.Because local performance maxima may exist in compositional spacesbetween those evaluated in the primary screening of the first librariesor alternatively, in process-condition spaces different from thoseconsidered in the first screening, it may be advantageous to screen morefocused candidate libraries (e.g., libraries focused on a smaller rangeof compositional gradients, or libraries comprising test fluids orfabrics having incrementally smaller compositional variations relativeto those of the identified hits) and additionally or alternatively,subject the initial hits to variations in process conditions. Hence, aprimary screen can be used reiteratively to explore localized and/oroptimized compositional space in greater detail. The preparation andevaluation of more focused candidate libraries can continue as long asthe high-throughput primary screen can meaningfully distinguish betweenneighboring library compositions or compounds.

[0069] Once one or more hits have been satisfactorily identified basedon the primary screening, fabric care composition libraries focusedaround the primary-screen hits can be evaluated with a secondaryscreen—a screen designed to provide (and typically verified, based onknown materials, to provide) process conditions that relate with agreater degree of confidence to commercially-important processes andconditions than those applied in the primary screen. In many situations,such improved “real-world-modeling” considerations are incorporated intothe secondary screen at the expense of methodology speed (e.g., asmeasured by sample throughput) compared to a corresponding primaryscreen. Particular fabric care composition components (e.g.,surfactants, polymers, etc. as more fully described below), fabrics,and/or processing conditions having characteristics that surpass thepredetermined metrics for the secondary screen may then be considered tobe “leads.” If desired, additional candidate libraries focused aboutsuch lead materials can be screened with additional secondary screens orwith tertiary screens. Identified leads (compositions or processconditions) may be subsequently developed for commercial applicationsthrough traditional bench-scale and/or pilot scale experiments.

[0070] While the concept of primary screens and secondary screens asoutlined above provides a valuable combinatorial research model forinvestigating fabric care compositions, components thereof, fabrictreatments, fabric compositions, fabric treatments and/or processconditions, a secondary screen may not be necessary for certainsituations in which primary screens provide an adequate level ofconfidence as to scalability and/or where market conditions warrant adirect development approach. Similarly, where optimization of materialshaving known properties of interest is desired, it may be appropriate tostart with a secondary screen. In general, the systems, devices andmethods of the present invention may be applied as either a primary or asecondary screen, depending on the specific research program and goalsthereof.

[0071] In one generally preferred approach, a test sheet of fabric 64comprising a plurality of test regions 68 is provided (FIG. 3). Each ofthe plurality of test regions 68 is simultaneously contacted with adifferent test fluid, and the plurality of test regions and/or theplurality of contacted test fluids are then screened, preferablysimultaneously screened, for a property of interest with respect tofabric care (i.e., a fabric property of interest) to evaluate therelative efficacy of the different test fluids with respect to thatproperty of interest. In this test-fluid varying embodiment, theplurality of test regions 68 preferably comprises the same, orsubstantially the same fabric composition, such that the differences intest fluid can be directly evaluated. The plurality of test regions 68may alternatively comprise different fabric compositions, such thatdifferences in test fluids and differences in fabric composition (e.g.,fabric pretreatments) can be evaluated in a single experiment. Theplurality of test regions 68 of the test sheet of fabric are preferablysubstantially isolated from each other.

[0072] A non-limiting example of this approach may includesimultaneously contacting a plurality of test regions 68 of the samedyed test sheet of fabric with different dye-affecting agents—such asdye-fixing agents or anti-dye-transfer agents. Following such contact,the plurality of test regions 68 can be screened, for example, todetermine the effectiveness of the dye-fixing agents. Additionally oralternatively, the differing contacted test fluids can be screened, forexample, to determine the effectiveness of the anti-dye-transfer agents(e.g., by evaluating whether the anti-dye-transfer agents scavengedreleased dyes into solution). As explained below, other fabric carecompositions and/or components or ingredients thereof can likewise beevaluated after such simultaneous contact with an appropriate screeningmethodology.

[0073] In another generally preferred approach, a test sheet of fabric64 comprising a plurality of test regions 68 is provided, where each ofthe plurality of test regions comprises a different fabric composition(e.g., differently treated regions of fabric sheet). As discussed below,the differing fabric compositions at the plurality of test regions 68are preferably prepared by simultaneously contacting each of testregions with different treatment fluids, and allowing the differingtreatment fluids (or components thereof) to interact with (e.g., adsorb,covalently bond, hydrogen bond, or ionic bond to or with) the fabric ateach of the plurality of test regions. Each of the plurality of testregions 68 (and hence, each of a plurality of different fabriccompositions) is simultaneously contacted with a test fluid, andpreferably with the same or substantially the same test fluid. Theplurality of test regions 68 are then screened for a fabric property ofinterest to evaluate the relative efficacy of the different fabriccompositions. This general approach can be referred to hereinafter as afabric-composition varying embodiment.

[0074] A non-limiting example of this generally-preferred approach mayinclude simultaneously treating a plurality of test regions 68 of a testsheet of fabric 64 with varying treatment agents (e.g., soil-inhibitingagents) to form a test sheet of fabric comprising different fabriccompositions at different test regions. The plurality of varying fabriccompositions can then each be screened for resistance to soiling bycontacting, and preferably simultaneously contacting the plurality offabric compositions with a soiling agent (preferably the same soilingagent), and then evaluating the effectiveness of the differingsoil-inhibiting agents with respect to that soiling agent.

[0075] In especially preferred variations of the immediatelyaforementioned preferred approaches (i.e., the test-fluid varyingembodiment and/or the fabric-composition varying embodiment), two ormore test sheets of fabric 64 are provided, with each of the two or moretest sheets of fabric comprising a plurality of test regions 68, andconversely, with each of the plurality of test regions comprising two ormore test sheets of fabric. The two or more test sheets of fabric 64 canbe the same or different from each other (i.e., can be the of the sameor different types of fabric and/or fabric compositions). In someapplications, the two or more test sheets of fabric are different fromeach other such that the potential for various interactions between thetwo or more test sheets of fabric can be evaluated at the correspondingtest regions. As an exemplary, non-limiting application, a white testsheet of fabric and a colored test sheet of fabric can screened asdescribed in the aforementioned preferred approaches, and the extent ofdye transfer between the first white test sheet of fabric and the secondcolored test sheet of fabric can be determined for various test fluidsand/or for various fabric compositions. The two or more test sheets offabric can, in this embodiment, be three or more, four or more, five ormore, six or more or seven or more test sheets of fabric 64. The numberof test sheets of fabric employed in combination ranges from about 2 toabout 20 or more, preferably from 2 to about 10 and most preferably from2 to about 7. Regardless of the exact number of test sheets of fabricemployed, the two or more (or 3 or more, etc.) test sheets of fabric 64preferably each comprise an integral seal 70 that isolates the pluralityof test regions 68 on each of the two or more (or 3 or more, etc.) testsheets of fabric.

[0076] The test sheet of fabric 64 can generally comprise any type offabric, including both woven and non-woven fabrics, and/or natural andman-made fabrics. The test sheet of fabric 64 is preferably a fabricused for garments (e.g., clothing, coats, etc.), for linens (e.g.,towels, bed sheets, etc.), for furniture, for draperies, and/or forother applications. Preferred fabric materials for the test sheet offabric include fabrics comprising natural materials such as cotton,wool, leather or silk, among others, or man-made materials such aspolyester, nylon, rayon, lycra or Gore-Tex™, among others.

[0077] The plurality of regions 68 of the test sheet of fabric 64 arepreferably isolated, or at least substantially isolated, from each otherwhile being contacted with the test fluid. As used herein, a pluralityof adjacent test regions of a common test sheet of fabric aresubstantially isolated from each other if a test fluid contacted with afirst test region does not substantially diffuse (e.g., bleed-through)to, or otherwise become exposed to, a second, adjacent, test regionduring the simultaneous contacting step. The extent of diffusion (e.g.,bleed-through) of the test fluid(s) between adjacent test regions ispreferably sufficiently small so as not to appreciably affectdetermination of the fabric property of interest for adjacent regions.In preferred embodiments, the plurality of adjacent test regions 68 arecompletely isolated from each other, such that a first test fluid samplecan be contacted with a first test region and a second test fluid samplecan be contacted with a second test region during the simultaneouscontacting step without any detectable affect on the determination ofthe fabric property of interest for the adjacent regions.

[0078] In especially preferred embodiments, the plurality of regions 68are isolated from each other using a seal, external to the test sheet offabric or integral therewith, together with the apparatus describedabove or other suitable device. The integral seal as disclosed hereincan provide substantially complete isolation between the wells, andtherefore, between adjacent regions of the test sheets of fabric—evenwhere the regions of the test sheet of fabric are exposed to the testfluids over long periods of time (e.g., even over an hour or more).Moreover, the integral seal is substantially robust with respect toapplication—in that it can provide substantial isolation of test regionsof the test sheet of fabric without being particularly sensitive tovariations in fabric types or properties, variations in test fluidcompositions or properties, device configuration and/or variations inwell-filling protocols (e.g., simultaneous, rapid serial, and/orslow-serial (e.g. in which adjacent wells are empty/filled and capillaryforces (e.g. wicking) can be relatively strong)). The integral seal isadvantageous, in particular, in applications where test sheets of fabriclacking an integral seal and/or lacking an external seal may otherwisedemonstrate cross-talk between adjacent regions under the conditions andfilling protocols of the experiment.

[0079] The plurality of regions can, however, in some embodiments andapplications, be isolated from each other without using an integral sealand/or without using any seal. In a preferred embodiment, one or moretest sheets of fabric lacking an integral seal, can be used in anapparatus of the present invention providing enhanced compressionbetween adjacent wells (e.g., having raised ridges 96 between each ofthe wells on one or both of the plates adjacent the one or more testsheets of fabric, as described above and shown in FIG. 4). Without beingbound by theory not specifically recited in the claims, thecompression-enhancing features (e.g., raised ridges) focus the pressureapplied by the screws onto very narrow inter-well regions, such that thefabric in these inter-well regions is strongly compressed between eachof the adjacent test regions of the test sheet. The inter-wellcompression of the test sheets of fabric greatly reduces the pore spaceavailable and thus serves to greatly slow down the diffusion of liquidfrom one cell to the next by reducing the effective cross section of thepores available for diffusion. In a preferred filling protocol, fairlygood isolation between test regions of the test sheet can be achieved ina configuration comprising one or more test sheets of fabric, even wheresuch test sheets lack integral seals, where the wells are filledsubstantially simultaneously or in rapid serial fashion, such that afilled well is not adjacent to an empty well for a period of timesufficient to cause undesired wicking and associated cross-talk betweenadjacent regions of the test sheet of fabric. The actual time thatadjacent empty and filled wells can coexist will vary depending onseveral factors, including fabric properties, test fluid properties, andthe particular apparatus employed in the screening, as discussed below.In a particularly preferred approach, inter-well compression can becombined with the substantially simultaneous or rapid serial filling ofadjacent wells—thereby minimizing and preferably substantially avoidingcross-talk between adjacent test regions of the test sheet of fabric.

[0080] Hence in the absence of an integral seal (and/or other sealingarrangement), the degree of cross-talk between adjacent wells may varydepending on the type of fabric (porosity, weave, compressibility,wettability, roughness, etc.), the degree of inter-well compression(e.g., effected in the described embodiment by matched sets of raisedridges between adjacent wells), and/or the filling protocols foradjacently-situated wells (e.g., slow sequential (serial) filling versusrapid-serial filling versus substantially simultaneous (parallel)filling). A skilled artisan can, based on the guidance provided herein,including for example, reference to the various examples, determinewhether a seal of any type, and in particular an integral seal, isadvantageous with respect to the particular application involved, oralternatively, whether a particular application can employ a test sheetof fabric without having a seal and/or without having an integral seal.In applications where the isolation of regions of the test sheet offabric is suitable without integral seals, the use of the inventiveapparatus together with one or more test sheets lacking integral sealscan result in reduced costs and complexity in preparing the fabrics,while still providing for meaningful experimental data for screeningmaterials as described herein, and without departing from the spirit ofthe invention.

[0081] Although the number of the plurality of test regions 68 can vary,the methods and apparatus described herein are particularly advantageousin connection with higher throughput parallel experiments. Hence, thenumber preferably of test regions is preferably at least 4, 8, 15, 24,40, 60, 90, 100, 200, 400, 500, 1000, 2000, 4,000, 10,000 or more. Inpreferred embodiments, # of test regions=96*N, where N is an integerranging from 1 to 100, preferably 1-10, and more preferably 1-5. Thesize, planar density, and/or geometrical arrangement of the test regionsare not narrowly critical, and can vary as described above in connectionwith the apparatus.

[0082] The test fluid may generally comprise elements, compounds orcompositions, and can typically include, without limitation, polymers,surfactants, dyes, bleaches, perfumes, buffers, electrolytes, builders,sequestering agents, flame retardants, and/or enzymes, alone or invarious combinations and permutations. The test fluid is preferably aliquid test fluid (e.g., solution, dispersion and/or emulsion), but canalso include gaseous test fluids. In the test-fluid varying embodimentdescribed above, two or more test fluids can differ from each other interms of overall concentration, in terms of chemical composition, or interms of other chemical or physical properties (viscosity, polymermolecular weight distribution, phase differences, acidity, etc.).Differences in chemical composition can be based, for example, on thepresence of differing components or on the presence of differing ratiosof the same components. Differences in test fluids can also be based ondifferences in their respective synthesis protocols, without actualcharacterization of the resulting test fluids. In an exemplary,non-limiting application, the test fluids can comprise one or morepolymers or polymer components. The polymers or polymer components candiffer with respect to composition, hydrophilicity, hydrophobicity,dipolar characteristics, charge, hydrogen-bonding characteristics,molecular weight and/or molecular weight distribution. In preferredapplications, the test fluids are fabric care compositions or potentialfabric care compositions being evaluated with respect to the fabricproperty of interest.

[0083] The fabric composition of the test sheet of fabric 64 at each ofthe plurality of test regions 68 may comprise the untreated fabric alone(by itself), as well as the fabric in combination with various treatmentagents (e.g. coatings, adsorbed moieties, bonded moieties (e.g.,covalently bonded moieties, ionically bonded moieties)), etc.).Typically, treatment agents can be employed in a fabric composition toeffect a change in one or more properties of the particular fabric,including without limitation, color fastness, polymer adsorption, soilrelease, stain release, dye retention, dye transfer, soil redeposition,abrasion resistance, fiber building, wrinkle reduction or prevention,static reduction or prevention, and texture. As such, in thefabric-composition varying embodiment of the invention, the plurality oftest regions 68 may comprise different fabric care compositions, wherethe compositions differ with respect to the underlying fabric materialand/or the treatment agents in each of the plurality of regions, suchthat variations exist in the one or more aforementioned properties ofthe fabric.

[0084] A treated fabric array suitable for use in the fabric-compositionvarying embodiment as a test sheet of fabric 64 comprising a pluralityof different fabric compositions at a plurality of test regions can beprepared according to any suitable method known in the art. Such atreated fabric array is preferably prepared, however, by the followingmethod, and most preferably, by the following method using the apparatusdescribed herein. Specifically, a plurality of test regions 68 of acommon test sheet of fabric are simultaneously contacted with aplurality of treatment fluids, where the plurality of treatment fluidsdiffer between the plurality of test regions. One or more components ofthe plurality of treatment fluids is allowed to interact with the testsheet of fabric at the plurality of test regions to form differentfabric compositions at the plurality of test regions.

[0085] The plurality of treatment fluids for preparing a treated fabricarray can, in an exemplary, non-limiting approach, comprise a polymercomponent that interacts with the test region of the test sheet offabric. The polymer component can vary between the different treatmentfluids with respect to composition, hydrophilicity, hydrophobicity,dipolar characteristics, charge, hydrogen-bonding characteristics,molecular weight, or molecular weight distribution, and/or otherproperties, such that different fabric compositions are formed on thetest sheet of fabric, with each fabric composition having a differentone or more polymers adsorbed onto the test region. The plurality oftreatment fluids can also vary, additionally or alternatively, withrespect to other types of components. In general, the plurality oftreatment fluids for preparing the treated array can differ with respectto concentration, chemical composition, or other chemical or physicalproperties. Differences in chemical composition can be based, forexample, on the presence of differing components or on the presence ofdiffering ratios of the same components. Differences in treatment fluidscan be characterized by differences in their respective synthesisprotocols, without actual characterization of the resulting fluids. Theresulting treated fabric array can, therefore, comprise a plurality oftest regions that differ with respect to the composition of the testsheet of fabric at each region.

[0086] The property of interest being evaluated with respect to fabriccare—referred to herein as a fabric property of interest—may be aproperty of the fabric itself, the fabric composition (e.g., treatedfabric) and/or a property of the test fluid. The particular fabricproperty of interest is not narrowly critical to the invention, and canvary, depending on the goals of the research purpose. In general, thefabric property of interest is a fabric property that has commercialsignificance. As such, the fabric property of interest can be anyproperty that affects one of the senses (e.g., look, feel, scent, sound,taste) of the end-user of the fabric, or at least a perception of one ofthe senses. Exemplary non-limiting fabric properties that are currentlyof interest include without limitation, color fastness, polymeradsorption, bonding (e.g., ionic or covalent bonding of a particularmoiety), soil release, stain release, dye retention, dye transfer, soilredeposition, abrasion resistance, fiber building, wrinkle reduction orprevention, static reduction or prevention, texture, friction (or lackthereof), strength, pilling, static electricity, or other optical,chemical, electrical or mechanical properties.

[0087] Fabric properties of interest can generally be measured ordetermined according to methods known in the art. The methods can beapplied in a serial (e.g., rapid serial) and/or simultaneous (i.e.,parallel) fashion. In preferred embodiments, the plurality of testregions are simultaneously screened for the fabric property of interest,such that the relative efficacy of the variable aspect of the experiment(e.g., of different test fluids, of different fabric-compositions, ofdifferent process conditions) can be evaluated in a single screeningexperiment (i.e., evaluated in parallel). Exemplary techniques that willfind applications with respect to determining fabric properties ofinterest include spectroscopic techniques (e.g., absorbance techniques,reflectance techniques, etc.), imaging techniques (e.g., digitalcamera), and mechanical property probing techniques (e.g., probing forpuncture strength), among others.

[0088] Particularly preferred properties of interest with respect tofabric care, as well as approaches for determining certain of suchfabric properties of interest are described above (e.g., color care),and/or in the following paragraphs. Such approaches are, in general,disclosed in connection with the apparatus disclosed herein. Except asspecifically recited in the claims, however, such reference to theparticular apparatus of the invention should be considered exemplary andnon-limiting.

[0089] Component (e.g., Polymer) Adsorption. A preferred fabric propertyof interest with respect to the present invention is the adsorption of acomponent of a fabric-care composition (e.g., a polymer component) to afabric. In order for an active ingredient in a detergent formulation tohave a strong effect, it is sometimes desirable or necessary for theingredient to be adsorbed to the surface of the fabric. This can beaccomplished either if the active ingredient itself has a favorablebinding interaction with the fabric surface, or if the active ingredientis chemically or physically attached to a second ingredient (e.g., apolymer) which has such an interaction. Accordingly, in many cases it isdesirable to be able to determine whether or not a given chemical orsubstance tends to adsorb to a fabric surface. A variety of methods aregenerally known to those skilled in the art; many of these methods canbe combined with the apparatus of the present invention to produce atest for adsorption which is parallel in nature and can be used to testmany substances at once.

[0090] Tests for adsorption of a substance, and typically and preferablya dissolved substance, to a surface can function in two ways. A changein some property of the fabric may be detected following adsorption,indicative of the presence of materials on the fabric which were notpresent prior to exposure to the solution; or a change in the solutionproperties may be measured, due to a reduction in the amount of thedissolved substance (since some if it has been deposited on the fabric).Which type of method is preferable will depend on the specific substanceand substrate, and on which types of physical or chemical analyticaltechniques can be applied to detect the above mentioned changes.

[0091] Within the context of the present invention, one skilled in theart may appreciate that almost any conventional method for detectingadsorption can be applied with the present invention. Generally, forexample, an array of solutions can be prepared, containing eitherdifferent dissolved substances to be tested in each well, or the samesubstance formulated in different ways, or some combination of the two.A clean test sheet of fabric (or fabric array) sample is also prepared.The chosen physical/chemical measurement can be made either on the cleanfabric or on the array of solutions, prior to exposure of the solutionsto the fabric. Then the fabric is placed in the inventive apparatus, andthe array of solutions are placed in the wells in the upper plate. Thepumping action of the membrane is used to flow the liquids back andforth through the fabric squares for some amount of time. Subsequently,either the liquids or the fabric or both may be analyzed again, todetect changes indicative of adsorption of the dissolved substances tothe fabric. The liquids may either be analyzed directly in/from themicrowasher plate, or may be removed to a separate plate for analysis.For analysis of the fabric, one will in general remove the fabric fromthe apparatus and rinse it to remove any of the substance which is notactually bound to the fabric surface. The fabric may then be dried, andan analysis done on the fabric to detect any adsorbed substance.

[0092] The following paragraphs illustrate several exemplary, andspecific embodiments of the above described methods as applied todetermination of polymer adsorption. It should be appreciated, however,by one of skill in the art, that other protocols may also be applied.The invention as disclosed herein provides a general platform whichallows almost any such test to be advantageously effected, andpreferably in a parallel fashion.

[0093] Many polymers contain features in their optical spectra(UV/visible/IR) which allow them to be identified. Alternatively,fluorescent moieties or dyes may be incorporated into a polymer(“tagging”) in a number of ways, such as: incorporation of trace amountsof a tagged monomer into the polymer backbone; tagging of the initiator,or of terminating or chain-transfer agents; or reaction of a tag with apolymer after synthesis. The concentration of the polymer in solution,before and after exposure to the fabric, may then be measuredspectroscopically, and the reduction in concentration due to adsorptionto the fabric may be determined. Alternatively, a spectroscopic or otheroptical assay may be applied to the fabric before and after exposure tothe solution. A specific example: if a polymer incorporates afluorescent moiety, then fluorescence may be detected in the array oftest solutions before and after exposure to the fabric; or the fabricitself may be scanned for fluorescence before and after exposure to thetest solutions.

[0094] In some cases, it may be necessary or desirable to carry out achemical reaction or other chemical interaction (other than making orbreaking covalent bonds) on the dissolved substances in order tomanifest their presence more easily. In general, a moiety of interest(e.g., the adsorbed moiety) may be reacted with a detection agent toform a detectable species, and the detectable species may then bedetected (e.g., with visual, spectroscopic or other optical methods asdescribed). For example, a dissolved substance (e.g., polymer) to bedetermined may be reacted with a detection agent to result in a colorchange of the solution, with an absorbance maximum at a particular knownwavelength. The strength of the absorbance can be proportional to theconcentration of the substance being determined.

[0095] The concentration of a polymer and changes therein may also bedetermined by viscosity measurements, since viscosity increases withconcentration of polymer. Methods for rapid measurement of viscosity onarrays of solutions have been described in the art, both with respect toparallel and/or serial approaches, including for example, in co-pendingapplication filed May 26, 2000 by Hadjuk et al., Ser. No. ______entitled “Instrument for High-Throughput Measurement of MaterialPhysical Properties and Method of Using Same.”

[0096] Polymer concentration may also be determined throughchromatography—samples of the solutions before and after exposure to thefabric are analyzed using any of a number of standard techniques, andthe peak area corresponding to the substance of interest can beintegrated to give a number proportional to the concentration before andafter exposure to the fabric. Methods for high speed chromatography havebeen described in the art, including for example in PCT patentapplication WO 99/51980 entitled “Rapid Characterization of Polymers”.

[0097] The wetting behavior of a drop of liquid deposited on the treatedfabric can also be used as a measure for ingredient (e.g., component)adsorption. If the fabric surface has been modified by adsorption of amaterial from a solution or dispersion or emulsion, then the behavior ofa drop of liquid which is deposited on the fabric can be differentdepending on the degree of adsorption. The drop may either bead up or beabsorbed/spread by the fabric in a different fashion. The extent ofwetting behavior can be calibrated through known methods with theparticular degree of adsorption.

[0098] Detergency. In order to test the efficiency of differentdetergent formulations on removing soils or stains, the followinggeneral method may be applied. A fabric array is first stained with aparticular type of soil, in as uniform a manner as possible. For examplethe soil may be applied by immersing the entire fabric in a solution andletting it dry. Uniformity can be improved by passing the wet fabricthrough a pair of rollers, to remove excess staining solution.Alternatively, the stain may be applied by brushing on the stainingsolution and letting it dry; by deposition from an automated pipettewith one or more tips; or by using a pin transfer tool, which is firstdipped in the staining solution and then dabbed on the fabric. Or thefabric may be placed in a container with particulate soils and shaken.The stained fabric can then be imaged by any of a number of means—with acamera (e.g., a digital camera, CCD camera, etc.), a flatbed scanner, ora scanning reflectance probe of some type. The data are preferablystored for use later in a comparative step.

[0099] Then the stained fabric array can then be placed in the inventiveapparatus. A different solution can be placed in each well, for examplecontaining different types of surfactants, bleaches, enzymes, etc. Thesolutions are forced back and forth through the fabric for a set time.Then the liquids are removed, and the fabric is removed, rinsed, dried,and imaged. A comparison of the images of the fabric from before andafter washing allows for a measurement of the degree to which the soilshave been removed by the different detergent formulations.

[0100] Optionally, a clean fabric array may be placed in the apparatustogether with the soiled one, in order to determine the degree of soilredeposition or soil transfer from the dirty fabric to the clean one.

[0101] Soil Release Due to Adsorption/Pretreatment. A known polymer(Gerol, manufactured by Rhodia) helps remove soils from synthetic(polyester) fibers in that the polymer is deposited on the clean fabricduring an initial washing. Soil which is subsequently deposited on thefabric is in contact with this adsorbed polymer layer, not with thefiber itself. When the soiled fabric is then washed again, the polymerlayer has the effect of aiding in the release of the soil, even if thepolymer was only present in the initial wash.

[0102] Polymers may be tested for this type of soil release mechanismand behavior using the inventive apparatus. A clean fabric array isinstalled in the apparatus. An array of solutions containing testpolymers is placed in the array, and flowed through the fabric for sometime to allow for the polymers to adsorb to the surface. The liquids andfabric are removed, and tested to detect adsorption of the polymer ifdesired. The fabric is then stained; imaged in the stained condition;washed; and imaged again, to gauge the effectiveness of the adsorbedpolymers (if any) on the release of subsequently deposited soils.Because the polymer has its effect due to being adsorbed during theinitial washing step, not the final soil removal washing step, the finalstep may be done with more conventional apparatus—i.e. the entire fabricmay be washed in a single vessel for the final soil removal step.

[0103] Color Testing. In many cases it is desirable to test the effectof a fabric care composition on the appearance of a fabric, specificallyon the color. Specific effects which are of interest include color lossfrom a fabric, and transfer or bleeding of color from one fabric toanother. These effects may be studied or tested in the inventiveapparatus using the following methods. Generally at least two pieces offabric will be installed in the apparatus. One fabric will generally bedyed or colored, and the other is not dyed or white.

[0104] A plurality of differing liquid compositions are placed in thedifferent wells, corresponding to the different fabric regions. Theliquid is made to circulate, preferably simultaneously, over and/orthrough the fabrics at each region, either by use of a flexible membraneas described earlier, or by some other method of agitation, in order toinsure that the fluid is in intimate contact with both fabrics. After aspecified time has passed, the liquid samples may be removed from theapparatus, for example using an 8-, 12-, or 96-tip pipetting apparatus,and placed in a separate microtiter plate for analysis. The remainingliquid in the apparatus is then poured out, and the wells and fabricregions are rinsed several times with clean water to remove anyremaining colored liquid. Then the fabrics are removed from theapparatus and dried.

[0105] One or more of the fabric which was initially colored, the fabricwhich was initially white, and/or the liquids removed from the wells maythen be analyzed to detect color changes. Each, or only one or two ofthese objects may be analyzed. For example, the fabric samples may beanalyzed using for example a scanning reflectance spectrophotometer or acolor imaging device such as a camera or scanner, and the liquid samplesmay be analyzed by a camera or a UV-vis spectrophotometer which isdesigned to handle 96 well plates (such as the Spectramax, manufacturedby Molecular Devices). One can observe the following types of effects:color loss or color change in the originally colored fabric; colorchange due to dye pickup on the white fabric; and color change in theliquid due to dye which remains dissolved and does not deposit on thewhite fabric. For example, one may in this manner distinguish betweencompositions which prevent dye loss from the colored fabric, andcompositions which do not inhibit such loss but do prevent the dye fromredepositing on the white fabric. These two cases are distinguished bythe absence or presence, respectively, of color in the wash liquid.

[0106] There are many other configurations of fabrics and testprocedures which can be used with the inventive apparatus for suchappearance-based tests, as will be obvious to one skilled in the art.For example, if only color loss is to be studied and one is notinterested in dye transfer (i.e. one is testing only for colorfastness),the white “pickup” cloth may be omitted, and the results assessed onlyfrom the color of the fabric sample after treatment, possibly augmentedby an analysis of the liquid. As another example, the behavior ofseveral different dyes or combinations of dyes may be analyzedsimultaneously, either by including several pieces of fabrics containingdifferent dyes, or a single piece of fabric dyed with multiple dyetypes. By colorimetric analysis of the fabric, the extent of bleeding ofthe different dye species may be determined more rapidly than would bepossible using a separate experiment for each dye type. In yet otherexamples, the inventive apparatus may also be employed to test new typesof molecules intended for use as dyes, either to determine the colorwhen applied to a fabric, or the extent of binding of the dye to a giventype of fabric. It may also be used to test the conditions under whichsuch dying is done, i.e. the formulation from which the dye isdelivered, which may contain such variables as ionic strength and pH, aswell as to test the use of auxiliary substances such as dye fixers whichaid in promoting strong binding of the dyes to the fabric.

[0107] Other specific screens for these and other specific properties ofinterest with respect to fabric care are known in the art, and or may bedeveloped in the future. Advantageously, such screening approaches andprotocols can be adapted for use in connection with the apparatus andmethods disclosed and claimed herein.

[0108] The apparatus may also be used for applications other than thosedescribed herein. For example, the apparatus shown in FIGS. 1A, 1B, and1C may be used as a parallel micro pump. Pressure can be created byinstalling inlet check valves into inlet passages in fluid communicationwith the fluid chambers and outlet check valves into outlet passages influid communication with the fluid chambers. When a vacuum is applied tothe cavities the inlet check valves open and the fluid chambers arefilled with fluid. When pressure is applied to the cavities, fluidwithin the chambers is pressurized and forced through the outlet checkvalves.

[0109] The apparatus may also be used as a parallel reactor forevaluating catalysts, and especially for evaluating heterogeneouscatalyst candidates. In such applications, plurality of heterogeneouscatalysts (or catalyst precursors) having different compositions can beincorporated into the apparatus such that the plurality of catalystcandidates are simultaneously contacted with a reactant containingfluid. The catalyst materials can be bulk, or supported catalystmaterials. The catalyst materials are preferably incorporated into theapparatus as part of the porous sheet 64 (e.g., with catalyst materialsat, on or in the test regions 68 of the porous sheet). In a particularlypreferred approach, the porous sheet 64 (or at least the test regionsthereof) can act as a porous support for the catalytically-activematerials. For example, the catalyst candidates (or catalyst precursors)can be impregnated into the test regions of the porous sheet, calcined,and then integrated into the parallel reactor. The catalyst materialscan also be deposited at, on or into the plurality of fluid chambers 54,for example, loosely, fixedly, formed as a film, contained within one ormore frits or other retaining mesh). The catalyst materials can, in afurther approach, be formed at, on or in the flexible membrane. In anyformat, each of the plurality of candidate catalysts are preferably,provided in discrete, separate test regions to avoid cross-talk betweencatalysts, and to provide for spatial deconvolution of catalystperformance. The pressure-induced agitation of the present invention canimprove the contact and mass transfer between the reactant-containingfluid and the heterogeneous catalyst. The parallel reactor 20, 84, 150is preferably configured as a parallel batch or semicontinuous reactor,and in some embodiments, could also be configured as a parallelcontinuous-flow reactor.

[0110] The following examples illustrate the principles and advantagesof the invention.

EXAMPLE 1 Preparation of Fabric Library Substrates with Integral Seal

[0111] The ink used for screen printing was a black Ultrasoft Plastisolfrom Union Ink Company (453 Broad Avenue, Ridgefield, N.J., 07657). Theink was diluted by adding approximately 30% reducing solution to reducethe viscosity and facilitate penetration of the ink through the porespaces and mesh of the cotton fabric. A 156 mesh screen was used inprinting, again to facilitate a high degree of ink flow into the fabric.The fabrics used were woven cotton fabrics. Immediately after printing,the ink was cured at about 230° C. for approximately 15 seconds. It wasfound empirically that a shrinkage of approximately 1% occurred duringthe curing process; therefore the screen pattern was fabricated at ascale of 101%, so that the final pattern after curing correspondedclosely to the desired 9.0 mm pitch.

[0112] The final step in preparation of the fabric samples was diecutting of the fabrics. This produced a sample which fit completelywithin a microtiter plate footprint (with no “overhang”), and which waspunched for adaptation with respect to each of the following: pin holesfor alignment with the apparatus; through holes or spaces for passage ofthe screws used in assembly; and a cut-out on one corner to allow forunambiguous definition of the orientation of the library and theidentity of cell (e.g., row 1, column 1).

EXAMPLE 2 Isolation Between Wells

[0113] Testing for the confinement of liquid to the individual cells(isolation) was effected by installing and sealing the test sheet,filling selected wells with a colored liquid, agitating, and thenobserving whether any wicking or diffusion of the liquid to an adjacentcell occurred. Such “crosstalk” was assessed using test sheets of wovencotton fabric having screen-printed integral seals, as well as withplain (unprinted) test sheets of fabric of the same material, butwithout the screen-printed integral seals.

[0114] The experimental conditions were controlled to evaluate two typesof forces that could impact the degree of crosstalk betweenwells—capillary forces (e.g., wicking) and diffusion forces. Asdemonstrated below, the distinction between the types of forces withrespect to crosstalk was particularly evident in connection with theplain, unprinted test sheets of fabric (lacking an integral seal). Assuch, the forces discussed herein are particularly relevant inconnection with such plain, unprinted test sheets of fabric. In one setof experiments, capillary forces (wicking) were examined in the contextof a first well containing liquid adjacent to a second empty well; inthat case, it was postulated, based on observed results disclosed below,that capillary forces would provide a strong driving force to pull theliquid into the empty neighboring well, where the fabric is dry. Such acondition could occur during research, for example, if a plate would befilled using a single-tip, 8-tip, or 12-tip liquid dispenser, whereinsome wells would be filled before others; or if an experiment would beperformed in which the contact time between liquid and fabric is avariable, such that some wells are intentionally filled before others.In a second set of experiments performed to examine isolation betweenadjacent wells, diffusion forces were examined in the context of twoneighboring wells that both contained substantially similar liquids, andthat differed only in the composition and/or concentration of adissolved species; in such cases, it was postulated, based on observedresults disclosed below, that capillary forces would be substantiallyabsent and that the transport of the dissolved species between wellswould occur, if at all, primarily by diffusion (rather than by capillaryflow or wicking of the solvent and solute).

[0115] The colored liquid used in each of the tests was a solution ofthe dye Direct Yellow 4 (CAS number 3051-11-4, available from Aldrich(Milwaukee, Wis.)) at a concentration of 0.5 mg/ml in demineralizedwater. The clear liquid used in each of the tests was demineralizedwater. The volume of liquid in each well was 400 μl in all cases.Isolation was evaluated under four different sets of experimentalconditions, summarized as follows:

[0116] Experiment IA: no integral seal; all wells either containedcolored liquid or left empty.

[0117] Experiment IB: integral seal; all wells either contained coloredliquid or left empty.

[0118] Experiment IIA: no integral seal; all wells contained eithercolored or clear liquid.

[0119] Experiment IIB: integral seal; all wells contained either coloredor clear liquid.

[0120] As noted above, the conditions of Experiments IA and IB testedisolation under conditions where capillary forces were deemed to be moreimportant, whereas the conditions of Experiments IIA and IIB testedisolation under conditions where capillary forces were postulated asbeing substantially absent and where diffusion was deemed to dominatethe transport of liquid or dissolved species between wells.

[0121] A microwasher apparatus was assembled in each of the ExperimentsIA, IB, IIA and IIB as follows. First, a single piece of a flexible,latex membrane was first installed directly adjacent to the base plateand adjacent to the cavities which were in communication with the sourceof controlled pressure. The flexible latex membrane was 0.006″ thick“Natural Latex Sheeting” from the Hygenic Corporation (part #08535).Then, for each of the experiments, three test sheets of fabric wereinstalled on top of the membrane and adjacent to each other—with each ofthe three test sheets in a given experiment either having or lacking theintegral seal (depending on the experiment as outlined above).

[0122] For Experiments IA and IB, the colored liquid was dispensed inserial fashion directly to the selected wells of the assembledmicrowasher apparatus by a liquid handling robot, with other remainingcells left empty. For Experiments IIA and IIB, the colored liquid andclear liquid were first dispensed into selected wells of a 2 mlpolypropylene microtiter plate, and were subsequently transferredsubstantially simultaneously to the loaded microwasher apparatus with anautomated 96-tip pipette. The substantially simultaneous transfer waseffected in order to minimize, and preferably substantially avoidcapillary flow during filling. Once the plates were filled, they wereplaced on the base station and pneumatically actuated for one hour,using a pressure differential of 3 psi and 7 inches Hg vacuum and acycle time of 0.5 seconds per complete cycle. An exception to thisgeneral protocol was made in connection with Experiment IA, where withinfive minutes after filling the wells and beginning agitation,significant wicking of the colored liquid to neighboring cells wasalready apparent, and the experiment was stopped after only ten minutesto avoid ending the experiment with a completely uniform coloring of thefabric, and to therefore preserve some vestige of the initial pattern ofcells filled with colored and clear liquids.

[0123] When agitation was complete, the remaining liquid was poured out,and the empty microwasher plates were placed in a convection oven at 50°C. for six hours, until the fabric was completely dry. Such drying wasdone to minimize colored liquid flow between cells when the apparatuswas disassembled and the constraints preventing flow were released. Inprinciple, such drying could be accelerated, for example, using theflexible membrane and pneumatic connection to provide convective flowair back and forth through the damp fabrics.

[0124] FIGS. 8-11 show the results of these experiments. The images ofthe fabrics were acquired using a Hewlett-Packard ScanJet 6200C flatbedscanner.

[0125] The image from Experiment IA (FIG. 8) shows that the coloredliquid readily wicked from one cell to the next in less than 10 minutesin the triple-stacked test sheet configuration, where each of the threetest sheets lacked an integral seal.

[0126] In contrast, the image from Experiment IB (FIG. 9) demonstratesthat the integral seals in each of the test sheets completely preventedwicking from occurring in the triple-stacked test sheetconfiguration—even over a one hour time period.

[0127] Moreover, the image from Experiment IIA (FIG. 10), shows thatfairly good isolation between wells can be obtained with the inventiveapparatus using triple-stacked test fabrics, even without an integralseal, where the wells are filled substantially simultaneously or inrapid serial fashion, such that a filled well is not adjacent to anempty well for a period of time sufficient to cause undesired wickingand associated cross-talk between adjacent regions of the test sheet offabric. (Compare Experiment IA). The actual time that adjacent empty andfilled wells can coexist will vary depending on several factors,including fabric properties, test fluid properties, and the particularapparatus employed in the screening, each of which is discussed furtherbelow. It is noted in this regard, that the partial wicking shown inFIG. 10 for the sample of Experiment IIA (without the integral seal)occurred predominantly during the drying stage; such partial wicking wasobserved to be substantially absent immediately after the one hourliquid exposure. Without being bound by theory not specifically recitedin the claims, the effectiveness of Experiment IIA (configured withtriple-stacked test sheets, each without an integral seal) wasattributed to the raised ridges between each of the wells on both thetop and bottom plates, which focus the pressure applied by the screwsonto very narrow regions, such that the fabric in these regions isstrongly compressed between each of the adjacent regions. The inter-wellcompression of the test sheets of fabric greatly reduces the pore spaceavailable and thus serves to greatly slow down the diffusion of liquidfrom one cell to the next by reducing the effective cross section of thepores available for diffusion. Hence, Experiment IIA demonstrates thatwhen such inter-well compression is combined with the substantiallysimultaneous filling of adjacent wells (or sufficiently rapid serialfilling of adjacent wells)—thereby minimizing and preferablysubstantially avoiding capillary forces (e.g. wicking) as the crosstalkmechanism—favorable results are achieved with respect to isolation ofindividual regions of the test sheet(s) of fabric.

[0128] The image from Experiment IIB (FIG. 11) demonstrates that theintegral seals in each of the triple-stacked test sheets also completelyprevented diffusion from occurring in the triple-stacked test sheetconfiguration over the one hour test period.

[0129] In summary, based on the results of Experiments IB and IIB(considered alone and/or in combination), the integral seal has beendemonstrated to effect substantially complete isolation between thewells, and therefore, between adjacent regions of the test sheets offabric, over long time scales. In the absence of an integral seal,results may vary depending on the type of fabric (porosity, weave,compressibility, wettability, roughness, etc.), the degree of inter-wellcompression (e.g., effected in the embodiment of this example by matchedsets of raised ridges between adjacent wells), and/or the fillingprotocols for adjacently-situated wells (e.g., very slow sequential(serial) filling versus substantially simultaneous (parallel) filling orsufficiently rapid-serial filling). Hence, in applications where it isdesirable or necessary to fill some adjacent wells at different timesthan other adjacent wells, rather than simultaneously, the use of anintegral seal and its associated superior isolation under a broaderrange of conditions presents definite advantages. In applications wherethe isolation of regions of the test sheet of fabric is suitable withoutintegral seals, however, use of the inventive apparatus together withone or more test sheets lacking integral seals can result in reducedcosts and complexity in preparing the fabrics, while still providing formeaningful experimental data for screening materials as describedherein, and without departing from the spirit of the invention.

EXAMPLE 3 Effect of Different Dissolved Substances on Dye Loss andTransfer

[0130] The materials used in this example are summarized as follows:

[0131] Poly(vinylpyrrolidone), Mw=55,000 (Aldrich, cat. #85,656-8),abbreviated as PVP; Poly(vinylpyridine N-oxide), Mw=200,000(Polysciences, cat #23684), abbreviated as PVP-N-O; Sandofix SWE Liquid(cationic dye fixer, Clariant product #260802), abbreviated as SWE;Sodium dodecyl sulfate (Aldrich 86,201-0), abbreviated as SDS.

[0132] A library of different test fluids was prepared from the startingmaterials and demineralized water as follows. 100 mg of each materialwas dissolved in 20 ml of demineralized water and agitated until fullydissolved. A formulation library was designed using Library Studio™graphical library-design software (available from Symyx Technologies,Inc., Santa Clara, Calif.). The design of the library, in table format,is shown in Table I (FIG. 12), where: the numbers in the table representthe mass fraction of each ingredient in the formulation recipe, in partsper million (ppm), with the remaining mass being demineralized water.The various materials and/or various amounts of materials for each ofthe different test fluids formulations were dispensed into wells inmicro-titer format using a singleam/single-tip liquid dispensing robot,controlled by Impressionist™ instrument control software (available fromSymyx Technologies, Inc., Santa Clara, Calif.). Specifically, 2 ml ofeach solution were formulated in the wells of a 2 ml polypropylenemicrotiter plate, by dispensing appropriate amounts of the polymer andsurfactant stock solutions and bringing the volume up to 2 ml with plaindemineralized water. The formulations were well mixed by sealing the topof the microtiter plate and shaking.

[0133] Referring further to Table I (FIG. 12), in the first three rows,only water and one polymer were present in each well. The concentrationof each polymer increased across each row from zero to 100 ppm insubstantially equal steps. In the fourth row, only water and surfactantwere present, and the concentration increased linearly from zero to 1000ppm. These numbers were chosen to be typical of the concentrations usedfor polymers and surfactants, respectively, in laundry detergentformulations. In rows five through seven, each well contained a singlepolymer as well as anionic surfactant. The polymer concentration wasfixed at 100 ppm, while the surfactant concentration increased from zeroto 1000 ppm. Finally, in row eight two different polymers were presentwithout surfactant. The total polymer concentration was fixed at 100ppm, but the relative proportions of the two polymers varied across therow.

[0134] The test fluids comprising the formulations contained in thelibrary were then screened with respect to dye transfer properties. Amicrowasher bottom plate was loaded as follows: a latex membrane wasinstalled first, closest to the cavities in the bottom plate. On top ofthe membrane were placed a red dyed fabric and a white fabric, in thatorder. The red fabric had been uniformly dyed with red dye #80(particular method of dying and total dye loading not known), and no dyefixers were used during or after dyeing. Both the red and white fabricshad previously been screen printed with an integral seal pattern asdescribed in Example 1. 400 μl of the formulation library wastransferred from the 2 ml plate to the wells of the microwasher plateusing a 96-tip robotic pipetting station (Cyberlab A400). Immediatelyafter transfer the microwasher plate was placed in the heated dockingstation (40° C.) and the pneumatic agitation was then turned on toagitate the uncovered microwasher assembly. The duration of agitationwas 30 minutes. When agitation was completed, the microwasher wasremoved from the docking station and 200 μl of the wash liquid wastransferred to a clear plastic microtiter plate using the 96-tippipette. The remaining liquid was poured out and the block was rinsedseveral times with clean water, to remove excess colored liquid. Thefabrics were then removed from the microwasher and allowed to air dry.

[0135] An image of the white fabric (with transferred dye) was thenrecorded using a Hewlett Packard ScanJet 6200C flatbed scanner, and isshown in FIG. 13A. The brightness, contrast, and gamma settings were setto values (255/0/1) which had been previously shown to produce anapproximately linear response to the reflectance of neutral density grayscale targets on a GretagMacbeth Color Checker chart. The recorded imagewas a 32-bit full color image (256 possible color values each for Red,Green, and Blue, per pixel) and was recorded at 150 pixels per inchresolution. This was sufficient to resolve the individual threads in thefabric without aliasing effects due to the interplay of the threadspacing and pixel spacing, which occur if the image resolution is notfine enough.

[0136] An image analysis program was used to extract averagered-green-blue (RGB) spectrum analysis coordinates from each square inthe array. An exemplary analysis program is described in U.S. patentapplication Ser. No. 09/415,772, filed Oct. 8, 1999 by Crevier et al.,entitled “Analysis of Chemical Data from Images.” In the program, thecenter of each square was located automatically, a circle was definedabout the center with a diameter of approximately one half the width ofthe square, and the RGB values of all pixels within the circle wereaveraged to obtain the numbers shown in Table II (FIG. 14). Rows 1-8 foreach color (red, green, blue) in Table II correspond to rows 1-8 of thetest regions shown in FIG. 13A. The color coordinate which is mostsensitive to the presence of the particular dye used in this example wasthe “green” or G coordinate, where maximum light absorption occurs. TheB coordinate was less sensitive, and there was almost no sensitivity inthe R coordinate at all (most red light was reflected). As is well knownto one skilled in the art of color analysis, various procedures may beused to calibrate the scanner's color response and convert RGBcoordinates (which may be specific to a particular imaging instrument),in good approximation, to more widely used systems (which may beabsolutely defined or more representative of more absolute values), suchas the CIE coordinates (x,y,Y) or (L,a,b). For reference purposes, theaverage RGB color coordinates for a plain white fabric array from thesame fabric lot and imaged with the same scanner under the sameconditions were: R: 223.6+/−2.97; G: 224.4+/−2.93; and B: 217.3+/−3.48.

[0137] The plate containing the liquid samples was analyzed in aSpectramax spectrophotometer (Molecular Devices). Spectra were obtainedover the range 400 to 600 nm with 10 nm resolution, and are shown inFIG. 15. Rows A-H in FIG. 15 correspond to rows 1-8 of test samples inFIG. 13B. The plate was also photographed with a digital camera, and agray scale image is shown in FIG. 13B. The contrast has been adjusted tobring out the color differences due to varying amounts of dye in thedifferent solutions. The contrast in the image of the fabric wassimilarly adjusted for display purposes.

[0138] Regardless of the specific interpretation of the data (which willbe discussed briefly below), several features are notable. Smoothvariations of the fabric and liquid color are observed across the rows,but the trends within each row are distinct from those in neighboringrows. This is consistent with isolation between neighboring wells, asdemonstrated in Example 2. Furthermore, cells which contain nominallyidentical chemical compositions yield nominally identical color results.For example, cells (1,1), (2,1), (3,1), and (4,1), (each as “row,column”) all contain only demineralized water. Referring to Table I, the“green” coordinates for these cells are 145, 144, 146, and 143respectively, well within the standard deviation of +/−3 observed for aplain white (undyed) fabric. As another example, cells (1,12), (5,1),and (8,12) contain 100 ppm of poly(vinylpyrolidone) and no surfactant.The “green” coordinates are 210, 211, and 208, respectively. Cells(2,12) and (6,1) contain 100 ppm of poly(vinyl pyridine-N-oxide) and nosurfactant, and the “green” coordinates are 220 and 222. Cells (3,12)and (7,1) contain 100 ppm of the SWE fixer polymer and no surfactant,and the “green” coordinates are 213 and 205. Thus, there is a welldefined relationship between the chemical composition of the liquidcontained in a well, and the amount of dye transfer from the red to thewhite fabric.

[0139] Trends observed in the library are discussed below with referenceto the graphs shown in FIGS. 16A, 16B, 16C, and 16D. FIG. 16Aillustrates the effect of polymer concentration with no surfactant; FIG.16B illustrates the effect of surfactant concentration with polymerfixed at 100 ppm concentration; FIG. 1 6C illustrates fabric reflectancefor a mixture of PVP and SWE; and FIG. 1 6D illustrates liquidabsorbance at 540 nm wavelength for a mixture of PVP and SWE.Poly(vinylpyrolidone), abbreviated PVP, and poly(vinylpyridine-N-oxide), abbreviated PVP-N-O, are both commonly used inlaundry detergent formulations as anti dye transfer (ADT) polymers.While they do not prevent dye loss from colored fabrics, they bind orscavenge free dye in solution and prevent it from redepositing on otherarticles of clothing. Thus the wash liquid attains a colored appearance,but other articles of clothing largely retain their original color anddo not pick up the dye which has been lost.

[0140] This is entirely consistent with the behavior observed in theexperiment, wherein dye transfer is strongly inhibited by both of thesepolymers, but significant amounts of dye are present in the solutions,as shown by comparison of the liquid image and spectrum (FIGS. 13B and15). In contrast, the Sandofix SWE polymer is a cationic dye fixer,which binds to both the cotton fabric and the dye molecules throughcharge interactions (cotton and the dye are both negatively charged,while the fixer is positively charged). Thus the fixer not only preventsdye transfer to the white fabric, but also prevents dye loss from thered fabric, as is most easily seen by looking at row 3 of the image andspectrum from liquid plate (FIGS. 13B and 15). The amount of dissolveddye is reduced as the fixer concentration is increased, opposite thebehavior observed for the other polymers.

[0141] The data also permit further semi-quantitative judgements to bemade. For example, PVP-N-O is readily seen to be a much more effectiveADT polymer than PVP, yielding a higher ultimate brightness and having alower threshold concentration for maximum activity. The superiority ofPVP-N-O to PVP in this regard is well known to those skilled in the artof laundry detergent formulation. In fact the G coordinate of 220 forPVP-N-O is almost equal to the value of 224 measured for a new piece ofundyed fabric. Also, the SWE fixer polymer yields poorer ultimateperformance as judged by the color of the white fabric, even thoughelimination of color in the liquid is a desirable property.

[0142] Thus qualitative and semi-quantitative judgements may be rapidlymade on the performance of single ingredients. Additionally,formulations may be studied using the apparatus, in which multiplecomponents with varying ratios are present. For example, in rows 5-7,the effect of the anionic surfactant SDS on the performance of the threepolymers is studied. The surfactant has only a minor effect on theperformance of the PVP and PVP-N-O polymers, but substantiallyeliminates the beneficial effects of the SWE fixer above a surfactantconcentration of about 500 ppm. This is due to the fact that thecationic polymer becomes complexed to the anionic surfactant andprecipitates. It is noteworthy that above 500 ppm SDS, the data for theSWE/SDS combination coincides almost exactly with that for pure SDS.

[0143] Also, it can be seen that adding anionic surfactant to the liquideven in the absence of any polymer leads to an increase in dye transfer,in comparison to plain demineralized water. This can be seen fromlooking at row 4 in FIGS. 13A, 13B, and 15, the data in Table II (FIG.14), and the corresponding graph in FIG. 16B. This occurs because thedye is charged; adding anionic surfactant increases the ionic strengthof the liquid and increases the solubility of the dye, since it reducesthe Debye screening length.

[0144] Finally, in row 8 a blend of PVP and SWE is studied, at fixedtotal polymer concentration. A smooth transition from dye fixing to antidye transfer behavior is observed, as is seen most clearly from theimage and data of the liquid samples. The best performance as judged bythe fabric color occurs at the endpoints, and thus little, if anything,appears to be gained by mixing these two polymers.

[0145] In light of the detailed description of the invention and theexamples presented above, it can be appreciated that the several objectsof the invention are achieved.

[0146] The explanations and illustrations presented herein are intendedto acquaint others skilled in the art with the invention, itsprinciples, and its practical application. Those skilled in the art mayadapt and apply the invention in its numerous forms, as may be bestsuited to the requirements of a particular use. Accordingly, thespecific embodiments of the present invention as set forth are notintended as being exhaustive or limiting of the invention.

[0147] Although the present invention has been described in accordancewith the embodiments shown, one of ordinary skill in the art willreadily recognize that there could be variations made to the embodimentswithout departing from the scope of the present invention. Accordingly,it is intended that all matter contained in the above description andshown in the accompanying drawings shall be interpreted as illustrativeand not in a limiting sense.

What is claimed is:
 1. A method for evaluating a test fluid as afabric-care composition or as a component thereof, the method comprisingproviding a test sheet of fabric comprising a plurality of test regions,simultaneously contacting each of the plurality of test regions with adifferent test fluid, and screening the plurality of test regions or thecontacted test fluids for a fabric property of interest to evaluate therelative efficacy of the different test fluids.
 2. The method of claim 1wherein two or more test sheets of fabric are provided, each of the twoor more test sheets of fabric comprising a plurality of test regions. 3.The method of claim 1 wherein two or more test sheets of fabric areprovided, each of the two or more test sheets of fabric comprising aplurality of test regions, at least two of the two or more test sheetsof fabric being different from each other.
 4. The method of claim 1wherein the plurality of test regions of the test sheet of fabric aresubstantially isolated from each other.
 5. The method of claim 1 whereinthe plurality of test regions are screened for a fabric property ofinterest.
 6. The method of claim 1 wherein the contacted test fluids arescreened for a fabric property of interest.
 7. The method of claim 1wherein the test sheet of fabric is woven.
 8. The method of claim 1wherein the test sheet of fabric is non-woven.
 9. The method of claim 1wherein the test fluid is a fabric-care composition.
 10. The method ofclaim 1 wherein the test fluid comprises one or more components selectedfrom the group consisting of polymers, surfactants, dyes, bleaches,perfumes, buffers, electrolytes, builders, sequestering agents, andflame retardants.
 11. The method of claim 1 wherein the test fluidcomprises a polymer.
 12. The method of claim 1 wherein the differenttest fluids comprise a polymer component, the polymer component varyingbetween different test fluids with respect to composition,hydrophilicity, molecular weight, or molecular weight distribution. 13.The method of claim 1 wherein the fabric property of interest isselected from the group consisting of color fastness, polymeradsorption, soil release, stain release, dye retention, dye transfer,soil redeposition, abrasion resistance, fiber building, wrinklereduction or prevention, static reduction or prevention, and texture.14. The method of claim 1 wherein the fabric property of interest ispolymer adsorption.
 15. The method of claim 1 wherein the plurality oftest regions are screened using a spectroscopic technique.
 16. Themethod of claim 1 wherein the plurality of fluid chambers are eight ormore fluid chambers, and the plurality of test regions are eight or moretest regions.
 17. The method of claim 1 wherein the plurality of testregions are simultaneously screened for the fabric property of interest.18. A method for evaluating a test fluid as a fabric-care composition ora component thereof, the method comprising providing a test sheet offabric comprising a plurality of test regions, each of the plurality oftest regions comprising a different fabric composition, simultaneouslycontacting each of the plurality of test regions with a test fluid, andscreening the plurality of test regions or the contacted test fluids fora fabric property of interest to evaluate the relative efficacy of thedifferent fabric compositions.
 19. The method of claim 18, wherein thetest sheet of fabric is a treated fabric array prepared by a methodwhich includes simultaneously treating each of the plurality of testregions with a plurality of treatment fluids, the plurality of treatmentfluids differing between the plurality of test regions.
 20. A method forpreparing a treated fabric array, the method comprising providing a testsheet of fabric comprising a plurality of test regions, simultaneouslycontacting each of the plurality of test regions with a plurality oftreatment fluids, the plurality of treatment fluids differing betweenthe plurality of test regions, and allowing one or more components ofthe plurality of treatment fluids to interact with the test sheet offabric at the plurality of test regions.